As is well known in the art, cotton pickers embody a plurality of rotating picker spindles arranged for systematic insertion into a cotton plant such that the picker spindles entwine or snag cotton from the plant. The picker spindles, with the cotton wound thereon, are then directed out of the path of the cotton plants and into operative association with a rotating doffer assembly to remove or strip the cotton from the spindles.
The doffer assembly typically comprises a series or stack of vertically spaced doffer elements carried on a driven vertical shaft. The doffer elements each typically include a disk with several doffer lugs or pads mounted thereunder, with the pads positioned so that they sweep over a horizontal row of rotating picker spindles which are projected into the doffer path. The doffer pads are typically formed of rubber, or a like elastomeric material, and in use they gradually wear away. Accordingly, periodic adjustment is required to maintain the correct spatial relationship between the doffer pads and the picker spindles having cotton wound thereon.
The proper spatial relationship between the doffer pads and the picker spindles is critical for proper performance of the picking operation. In most field conditions the doffer pads must just touch the picker spindle surface for proper removal of harvested lint from the spindles. However, some field conditions may require an interference between the doffer pads and the picker spindles surface to maximize performance of the picking operation.
It has heretofore been the practice to utilize a screw type adjustment arrangement to manually move the stack of doffer elements up or down in relationship to the picker spindles and to lock the doffer elements in a fixed vertical position. If the doffer elements are locked in position with the doffer pads either just touching or in interference with the picker spindles, this relationship will change in a short period of time as the doffer pads wear away on the surface of the spindles, and the contact or interference setting is lost. If the doffer elements are not readjusted, the picker spindles will tend to wrap with cotton lint. It has been found that under certain field conditions it is necessary to readjust the doffer elements one or more times a day to maintain the cleanliness of the picker spindles. An example of such a cotton picker doffer arrangement is disclosed in U.S. Pat. No. 2,664,689, assigned to the same assignee as the present invention.
It is therefore desirable to provide a cotton picker doffer arrangement which continuously and automatically adjusts the spatial relationship between the doffer elements and the picker spindles. This would eleminate a burden on the machine operator of observing the picker spindles and periodically adjusting the doffer elements to maintain clean spindles for correct harvesting efficiency. Neglect in doffer element adjustment is probably the main cause of premature doffer failure and machine downtime.